Blockchain in the Energy Sector: Applications, Challenges, and Future Directions

With decarbonization, decentralization, and digitalization, energy coordination increasingly involves many actors, heterogeneous cyber–physical data, and compliance-sensitive settlement workflows. Although blockchain has been widely discussed in this domain, existing studies are still fragmented across application-specific or platform-specific narratives. As a result, it remains difficult to compare recurring mechanisms across scenarios or to determine which blockchain functions are operationally justified in deployable energy systems. We address that fragmentation through a structured narrative review of 41 representative sources, including prior surveys, foundational technical references, and scenario-specific studies. We formulate three research questions concerning architectural positioning, cross-scenario mechanisms, and deployment barriers. On this basis, we synthesize a unified five-layer reference architecture that links off-chain physical infrastructure and trusted data acquisition to protocol-level trust anchoring, reusable business services, interface and compliance functions, and application scenarios. The framework is then used to compare five recurring scenario families, namely peer-to-peer energy trading, carbon markets and renewable energy certificates, electric vehicle charging and vehicle-to-grid services, virtual power plants, and grid flexibility coordination. The analysis shows that blockchain is most defensibly positioned as an evidence-and-settlement trust layer, rather than as a replacement for real-time physical control. It also identifies three persistent adoption bottlenecks, namely scalable ledger interaction, trustworthy cyber–physical data binding, and interoperability with regulatory and operational infrastructures. By making the trust boundary explicit and by providing a common analytical lens for cross-scenario comparison, this review clarifies the scientific contribution of blockchain to energy systems and outlines stakeholder-oriented directions for deployable hybrid designs.